This policy prevents the user from showing account details (email address or user name) on the sign-in screen. If you enable this policy setting, the user cannot choose to show account details on the sign-in screen. If you disable or do not configure this policy setting, the user may choose to show account details on the sign-in screen. Fix: (1) GPO: Computer Configuration\Administrative Templates\System\Logon\Block user from showing account details on sign-in (2) REG: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\System!BlockUserFromShowingAccountDetailsOnSignin